Do I have to ground pin 9 for better channel separation if I use AC for heater.
Thanks

Albert

yajnaS

21st February 2011 08:03 AM

Pin 9 is the shield, you need to ground it. Irrespective of the heater.

mastodon

21st February 2011 09:12 AM

I'd say so, yes. But I don't see the connection with using an AC heater. What's the story behind that?

DF96

21st February 2011 11:12 AM

If pin 9 is the shield, then it probably has nothing to do with the heater. If a shield is present, then it should either be grounded or attached to a cathode - basically you want it grounded for AC, and negative for DC. The former ensures that it does act as a shield and reduces capacitive coupling between valve sections; the latter ensures that it does not pick up stray electrons.